25-Hydroxy vitamin D3 compositions

ABSTRACT

An oil composition containing 25-hydroxy Vitamin D 3  and an oil is provided. In addition an emulsion, a microencapsulated oil composition, and a feed premix composition each containing 25-hydroxy Vitamin D 3  are provided. Methods of making an oil composition, a microencapsulated oil composition, and a feed premix containing 25-hydroxy Vitamin D 3  are also provided.

This application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/350,301, filed Jan. 15, 2002.

FIELD OF THE INVENTION

The present invention relates to compositions containing 25-hydroxy Vitamin D₃, including oils, emulsions, microencapsulated oils, and feed premixes. The invention also relates to methods of making and using such compositions.

BACKGROUND OF THE INVENTION

Vitamins are useful as nutritional supplements in the diet of various animals. Vitamins act as catalysts in nearly every biochemical pathway. For that reason vitamin deficiency leads to numerous diseases and physical ailments.

Vitamin D₃ is implicated in numerous diseases. Too much or too little Vitamin D₃ in the parathyroid can lead to hyperparathyroidism, hypoparathyroidism, pseudohypoparathyroidism, and secondary hyperparathyroidism. In the pancreas Vitamin D₃ is implicated in diabetes. In the liver, problems with Vitamin D₃ can lead to cirrhosis, and obstructive jaundice. Vitamin D₃ is intimately involved in the regulation of calcium levels and in the bone is implicated in fibrogenisis imperfecta ossium, osteitis fibrosa cystica, osteomalacia, osteoporosis, osteopenia, osteosclerosis, renal osteodystrophy, and rickets. In the intestine, Vitamin D₃ plays a role in glucocorticoid antagonism, idiopathic hypercalcemia, malabsorption syndrome, and tropical sprue. Psoriasis in the skin, medullary carcinoma in the thyroid, sarcoidosis in the lung, and hypophosphatemic VDRR and chronic renal disease in the kidney are all affected by the levels of Vitamin D₃ in the body.

Vitamin D₃ is produced by the skin under normal sunlight conditions through the oxidation of cholesterol. Vitamin D₃ is then converted by the liver into 25-hydroxy Vitamin D₃. Finally, 25-hydroxy Vitamin D₃ is converted by the kidney into 1α,25(OH)₂ Vitamin D₃, which is active in various biochemical pathways.

The production of 1α,25(OH)₂ Vitamin D₃ is shown below.

25-hydroxy Vitamin D₃ is a reservoir of the downstream 1α,25-hydroxy Vitamin D₃ in the body. When the level of Vitamin D₃ is adequate, 25-hydroxy Vitamin D₃ is stored in the liver. It is released from the liver, as required, and further processed by the kidney into the active molecule.

For these reasons, it is useful to provide 25-hydroxy Vitamin D₃ to animals as a nutritional supplement. Formulations containing 25-hydroxy Vitamin D₃ are sold under the trademark HY-D (Roche Vitamins Inc., Parsippany, N.J.).

Unfortunately, 25-hydroxy Vitamin D₃ is unstable under conventional storage conditions, resulting in a time-dependent loss of activity per unit mass. Among other things, 25-hydroxy Vitamin D₃ is prone to oxidation, particularly during storage over extended periods of time. Such degradation can adversely affect dosing of 25-hydroxy Vitamin D₃ when incorporated into animal feeds.

It would, therefore, be advantageous to provide 25-hydroxy Vitamin D₃ compositions with improved stability characteristics under a wide spectrum of conditions and in combination with various nutritional additives. These and other objects of the present invention are described in greater detail below.

SUMMARY OF THE INVENTION

The present invention provides an oil composition containing an oil and 25-hydroxy Vitamin D₃, wherein the 25-hydroxy Vitamin D₃ is dissolved in the oil in an amount between about 5% and 50% by weight based on the total weight of the oil composition.

The present invention also provides an emulsion comprising an aqueous composition and an oil composition, wherein the oil composition comprises 25-hydroxy Vitamin D₃ dissolved in the oil in an amount between about 5% and about 50% by weight based on the total weight of the oil composition.

Also provided is a microencapsulated oil comprising an oil composition and an encapsulation agent encapsulating the oil composition, wherein the oil composition contains 25-hydroxy Vitamin D₃ dissolved in an amount between about 5% and 50% by weight based on the total weight of the oil composition. In addition, a method of making the microencapsulated oil is provided, comprising providing an oil composition wherein 25-hydroxy Vitamin D₃ is dissolved in an oil in an amount between about 5% and 50% by weight based on the total weight of the oil composition, and encapsulating the oil composition in encapsulating agent.

The present invention also provides a feed premix composition comprising a microencapsulated oil of the invention admixed with at least one nutritional additive. Also provided is a method of making the feed premix composition, comprising providing a microencapsulated oil comprising an oil composition, wherein 25-hydroxy Vitamin D₃ is dissolved in an oil in an amount between about 5% and about 50% by weight based on the total weight of the oil composition encapsulated in an encapsulating agent. The microencapsulated oil composition is then admixed with a nutritional additive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the % Vitamin D₃ retention of 25-hydroxy Vitamin D₃ (% active ingredient by weight of total composition) in microencapsulated oils according to the present invention as compared to a prior art formulation at various storage times at 11° C.

FIG. 2 shows the percent retention of 25-hydroxy Vitamin D₃ in microencapsulated oils according to the present invention as compared to a prior art formulation at various storage times at 11° C.

FIG. 3 shows the % Vitamin D₃ retention of 25-hydroxy Vitamin D₃ (% active ingredient by weight of total composition) in microencapsulated oils according to the present invention as compared to a prior art formulation at various storage times at 25° C.

FIG. 4 shows the percent retention of 25-hydroxy Vitamin D₃ in microencapsulated oils according to the present invention as compared to a prior art formulation at various storage times at 25° C.

FIG. 5 shows the linear regression of 25-hydroxy Vitamin D₃ retention data for microencapsulated oils according to the present invention as compared to a prior art formulation at various storage times at various temperatures.

FIG. 6 shows the percent retention in of Vitamin D₃ and 25-hydroxy Vitamin D₃ in prior art and 25-hydroxy Vitamin D₃ Basic Premixes of the present invention.

FIG. 7 shows the percent retention of Vitamin D₃ and 25-hydroxy Vitamin D₃ in prior art and 25-hydroxy Vitamin D₃ Vitamin Premixes of the present invention.

FIG. 8 shows the percent retention of Vitamin D₃ and 25-hydroxy Vitamin D₃ in prior art and 25-hydroxy Vitamin D₃ Complete Premixes of the present invention.

DETAILED DESCRIPTION. OF THE INVENTION

The present invention provides an oil composition containing an oil and 25-hydroxy Vitamin D₃, wherein the 25-hydroxy Vitamin D₃ is dissolved in the oil in an amount between about 5% and 50% by weight based on the total weight of the oil composition. These oil compositions may be advantageously incorporated into many other compositions, especially emulsions, microencapsulated oils, and feed premixes.

The oil employed in the present invention may be any edible oil or fat, preferably having a high content of lauric acid, e.g., babassu oil, coconut oil, cohune oil, murumyru tallow, palm kernel oil, tucum oil. The oil may be natural, synthetic, semisynthetic, or mixtures thereof. Natural oils may be derived from any source, e.g., animal, plant, fungal, marine. Synthetic and semisynthetic oils may be produced by any convenient means.

Preferred oils are coconut oil, babassu oil, cohune oil and palm kernel oil.

25-hydroxy Vitamin D₃ may be obtained from any source. For example, the production of 25-hydroxy Vitamin D₃ is described in U.S. Pat. No. 3,565,924, and the isolation of 25-hydroxy Vitamin D₃ is described in U.S. Pat. No. 4,310,467.

The oil composition may be prepared by any convenient means. Generally, crystals of 25-hydroxy Vitamin D₃ are dissolved in the oil by heating with agitation. Preferably, the oil is first placed in an appropriate vessel and heated to the desired temperature. Thereafter, 25-hydroxy Vitamin D₃ is added to the oil, in an appropriate amount, while maintaining the temperature of the oil or increasing it over time. The oil composition is then agitated for a time sufficient to dissolve the crystals of the 25-hydroxy Vitamin D₃. Prior to addition to the oil, the 25-hydroxy Vitamin D₃ crystals may be reduced in size by any convenient means, including, milling and/or sieving, to enhance dissolving. Agitation may be accomplished by any convenient means, including stirring, vessel rotation, mixing, homogenization, recirculation, and ultrasonication.

Conveniently, the oil is heated to 80-85° C., the 25-hydroxy Vitamin D₃ is introduced into the vessel, and the temperature is maintained over two hours while stirring the oil composition.

Generally, 25-hydroxy Vitamin D₃ is dissolved in the oil in an amount between about 5% and 50% by weight, based on the total weight of the oil composition. Preferably, the 25-hydroxy Vitamin D₃ is dissolved in the oil in an amount between about 10% and 40% by weight based on the total weight of the oil composition; more preferably, in an amount between about 12.5% and 28%; and even more preferably, in an amount between about 15% and 25%

The oil composition may optionally contain any other suitable material including, but not limited to, antioxidants, preservatives, dissolution agents, surfactants, pH adjusting agents or buffers, humectants, and mixtures thereof.

Suitable antioxidants include mixed tocopherols, tocopherols from natural or synthetic sources, ethoxyquin (EMQ) (6-ethoxy-1,2-dihydro-2,2,4-trimethyl-quinoline), butylated hydroxy toluene (BHT), butylated hydroxy anisole (BHA), natural antioxidants like rosemary extract, propyl galate, and mixtures thereof. Preferably, the antioxidant is EMQ.

Suitable preservatives include methyl paraben, propyl paraben, potassium sorbate, sodium benzoate, benzoic acid, and mixtures thereof. Suitable dissolution agents include inorganic or organic solvents, including alcohols, chlorinated hydrocarbons, and mixtures thereof.

Surfactants may be anionic, cationic or nonionic. Suitable surfactants include ascorbyl palmitate, polysorbates, polyethylene glycols, and mixtures thereof. Suitable pH adjusting agents or buffers include citric acid-sodium citrate, phosphoric acid-sodium phosphate, acetic acid-sodium acetate, and mixtures thereof. Suitable humectants include glycerol, sorbitol, polyethylene glycol, propylene glycol, and mixtures thereof.

As appears, the enhanced stability of the various compositions of the present invention is attributable to a physical separation of the labile 25-hydroxy Vitamin D₃ component on the one hand, and minerals, transition metals, and/or peroxides often added to animal feed premixes and animal feeds, on the other hand. This enhanced stability is of practical advantage, as shown in the comparative data in the Examples below. Preferably, therefore, the oil compositions of the invention do not contain any minerals, transition metals, or peroxides.

Once formed, the oil composition of the invention may be incorporated in various other useful compositions, some of which are discussed below. For example, emulsions may be formed, which may be converted into various encapsulated oils having superior stability properties.

A variety of emulsions may be prepared by combining the oil compositions described above with an aqueous composition. The emulsion may be of any type. Suitable emulsions include oil-in-water emulsions, water-in-oil emulsions, anhydrous emulsions, solid emulsions, and microemulsions. The emulsions may be prepared by any convenient method.

The emulsions contain an aqueous composition and an oil composition, wherein the oil composition comprises 25-hydroxy Vitamin D₃ dissolved in an oil in an amount of between about 5% and about 50% by weight based on the total weight of the oil composition. As used herein, the terms “aqueous composition” and “aqueous phase” are used interchangeably.

Generally, the emulsion contains from about 20% to about 95% of an aqueous composition, and from about 5% to about 80% of an oil composition. Preferably, however, the emulsion contains from about 85% to about 95% of an aqueous composition, and from about 5% to about 15% of an oil composition.

Conveniently, the oil composition may be dispersed as droplets in the aqueous composition. For example, the droplets may have a mean diameter of less than about 500 nm in the aqueous composition. Conveniently, the droplets have a mean diameter of between about 100 nm and about 200 nm.

In a particularly advantageous embodiment, the emulsion contains an encapsulating agent, which facilitates microencapsulating the oil composition upon further processing of the emulsion, e.g., by spray drying. As used herein, the terms “encapsulating agent” and “encapsulation agent” are used interchangeably.

The encapsulating agent may be any edible substance capable of encapsulating the oil composition. Preferably, the encapsulating agent is capable of eliminating contact between the 25-hydroxy Vitamin D₃ and the environment when the oil composition is encapsulated by the encapsulating agent. Preferably, the encapsulation agent is predominantly a colloidal material. Such materials include starches, proteins from animal sources (including gelatins), proteins from plant sources, casein, pectin, alginate, agar, maltodextrins, lignin sulfonates, cellulose derivatives, sugars, saccharides, sorbitols, gums, and mixtures thereof.

Suitable starches include: plant starches (e.g., CAPSUL® (National Starch & Chemical Corp., New York, N.Y.), HI-CAP® (National Starch & Chemical Corp., New York, N.Y.)), other modified food starches, and mixtures thereof. Preferably, the starch is CAPSUL®.

Suitable proteins from animal sources include: gelatins (e.g., bovine gelatins, porcine gelatins (Type A or B) with different Bloom numbers, fish gelatins), skim milk protein, caseinate, and mixtures thereof. Preferably, the protein from an animal source is a gelatin. Suitable proteins from plant sources include: potato protein (e.g., ALBUREX® (Roquette Preres Societe Anonyme, Lestrem, France)), pea protein, soy protein, and mixtures thereof. Preferably, the protein from a plant source is ALBUREX® potato protein.

Suitable maltodextrins with a different dextrose equivalent include: maltodextrin 5, maltodextrin 10, maltodextrin 15, maltodextrin 20, maltodextrin 25, and mixtures thereof. Preferably, the maltodextrin is maltodextrin 15.

Suitable cellulose derivatives include: ethyl cellulose, methylethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, carboxymethylcellulose, and mixture thereof. Suitable saccharides include lactose, sucrose, or mixtures thereof. Preferably, the saccharide is sucrose. Suitable gums include: acacia, locust bean, carragean, and mixtures thereof. Preferably, the gum is gum acacia.

When the emulsion of the invention contains an encapsulating agent, the encapsulating agent may be dispersed in water by any suitable means to form an aqueous phase. The aqueous phase may be a solution or a mixture depending on the properties of the components selected. The selected components may be dispersed by any suitable means including: homogenizing, mixing, emulsifying, recirculating, static mixing, ultrasonication, stirring, heating, and combinations thereof. The viscosity of the resulting aqueous phase may then be adjusted, as desired, by the addition of water.

The aqueous composition of the emulsion may optionally contain any other suitable material including but not limited to, those discussed above in reference to the oil composition. Preferably, the aqueous composition may include, an encapsulating agent, a film-forming agent, a plasticizer, a preservative, an antioxidant, and mixtures thereof.

Suitable antioxidants include sodium ascorbate, ascorbic acid, citric acid, and mixtures thereof. Suitable preservatives include methyl paraben, propyl paraben, sorbic acid, potassium sorbate, sodium benzoate, and mixtures thereof.

Preferably, the aqueous phase contains a modified food starch, such as octenyl succinyl starch (CAPSUL®), maltodextrin, and sodium ascorbate. The selected components may be dissolved in water by any suitable means, preferably stirring. The final viscosity of the resulting aqueous phase may then be adjusted to the desired viscosity, preferably about 250 to about 450 cp, more preferably about 300 to about 400 cp, even more preferably about 385 cp.

Another preferred aqueous phase contains potato protein (ALBUREX®), maltodextrin 20, and sodium ascorbate. The selected components are dispersed into the water, preferably by homogenization. The mixture is preferably homogenized until it is uniform and lump-free. Preferably, the homogenization is carried out at a temperature between about 50° C. and about 75° C.

Preferably, the emulsion compositions of the invention should not contain any mineral, transition metal, or peroxide.

The emulsion may be formed by emulsifying the oil composition and the aqueous phase by any means, including homogenization, rotor-stator shear, high pressure shear and cavitation, high speed “cowles” or shear agitation, and combinations thereof. The volume and viscosity of the emulsion may preferably be adjusted by the addition of water after emulsification.

Conveniently, the oil composition and aqueous composition are emulsified by homogenization.

As noted above, the emulsion may be incorporated or employed in producing other useful compositions, especially microencapsulated oils, e.g., spray dried powders.

Generally, the microencapsulated oils comprise an oil composition and an encapsulation agent encapsulating the oil composition, wherein the oil composition contains 25-hydroxy Vitamin D₃ dissolved in the oil in an amount between about 5% and about 50% by weight based on the total weight of the oil composition.

The microencapsulated oil may be produced by any convenient means. Conveniently, the oil composition is encapsulated by drying an emulsion described above by any suitable means, including spray drying, freeze drying, fluid bed drying, tray drying, adsorbtion, and combinations thereof. Preferably, the microencapsulated oil is produced by spray drying an emulsion having an aqueous phase as defined above containing an encapsulation agent. The spray drying parameters are dictated by the physical characteristics desired in the final microencapsulated oil. Such physical parameters include particle size, powder shape and flow, and water content.

Low concentrations of oil in the microencapsulated oil relative to the 25-hydroxy Vitamin D₃ leads to enhanced protection of the 25-hydroxy Vitamin D₃ and high recovery of the 25-hydroxy Vitamin D₃ during the encapsulation process. Conveniently, the oil is in an amount less than about 30% by weight based on the total weight of the microencapsulated oil; more conveniently, less than about 20%, more preferably, less than about 10%; and even more preferably, less than about 5%.

The microencapsulated oil should have good flowability and the 25-hydroxy Vitamin D₃ should be distributed homogeneously throughout the composition. Conveniently, the microencapsulated oil is a powder.

Any other suitable additive may be added to the microencapsulated oil. One such additive may be a flow agent such as silicon dioxide, to increase the flowability of the microencapsulated oil.

The microencapsulated oil may be incorporated into or employed in producing various other useful compositions, including feed premix compositions.

For example, the invention provides a feed premix composition containing a microencapsulated oil of the invention and at least one nutritional additive.

As used herein the term “nutritional additive” means any substance added to animal feeds and animal feed premixes to add nutritional value to the product, to adjust the nutritional value of the product, or to aid in the addition of nutritional value to the product. Suitable nutritional additives include: vitamins, pro vitamins, minerals, active phytase, amino acids, carotenoids, starches, fish meal, choline, medicinal additives, carriers, and combinations thereof.

Suitable vitamins include all vitamins and derivatives thereof (Vitamin A, Vitamin E, Vitamin B₁₂, Vitamin B₃, Niacin, d-pantothenic acid, Folic Acid, Vitamin B₆, Vitamin B₁, Vitamin D₃, Vitamin C, Vitamin B₂, and combinations thereof.) Any pro vitamin or mixture of pro vitamins may be employed, such as beta-carotene. Suitable minerals and their salts include manganese, zinc, iron sulfate (monohydrate), copper oxide, cobalt sulfate Iodine, selenium, and combinations thereof.

Any suitable amino acid may be employed. Suitable carotenoids include: CAROPHYLL® Red (Roche Vitamins Inc., Parsippany, N.J.), beta carotene, astaxanthin, and combinations thereof. Suitable starches include: corn starch, wheat starch, potato starch, tapioca starch, and combinations thereof.

Suitable medicinal additives include: pharmaceuticals, performance enhancers, antibiotics, antioccidials, and mixtures thereof. Suitable carriers include: limestone, wheat middlings, corn meal, rice hulls, calcium carbonate, and combinations thereof.

Conveniently, the feed premix composition contains Vitamin A, Vitamin E, Vitamin B₁₂, Vitamin B₃, niacin, d-pantothenic acid, folic acid, Vitamin B₆, Vitamin B₁, limestone, and rice hulls.

Another preferred feed premix composition contains Vitamin E, Vitamin B₃, cartenoids, choline chloride, manganese oxide, zinc oxide, iron sulphate, copper oxide, cobalt sulphate, and wheat middlings. Still another preferred feed premix composition of the invention contains a phytase enzyme.

The feed premix composition may be produced by any convenient means known in the art by combining the microencapsulated oil with any selected nutritional additives; including by mixing, adhesion, dispersion of the microencapsulated ingredient in an appropriate solvent and spraying onto the nutritional additive, and combinations thereof. Conveniently, the feed premix composition is produced by mixing the microencapsulated oil with any selected nutritional additives.

The feed premix compositions may be added to a variety of animal food products. For example, they may be added to poultry (e.g., fryers, broilers, layers, turkeys) feed, swine, canine, and feline feed.

Generally, the premix is combined with the animal food product in an amount to provide 50 ppb to 200 ppb (parts-per-billion) 25-hydroxy Vitamin D₃ based on the finished feed.

The following examples are provided to further illustrate the compositions and methods of the present invention. These examples are illustrative only and are not intended to limit the scope of the invention in any way.

EXAMPLES Example 1 Oil Compositions

Oil compositions of the present invention are prepared by dissolving 25-hydroxy Vitamin D₃ in an oil with heating and/or agitation, in the following proportions.

TABLE 1 Oil compositions. Amount of 25-hydroxy Amount of % wt of 25-hydroxy Vitamin D₃ Oil Oil (g) Vitamin D₃ 5 Coconut 95 5 5 Palm Kernel 95 5 10 Coconut 90 10 10 Palm Kernel 90 10 15 Coconut 85 15 15 Palm Kernel 85 15 20 Coconut 80 20 20 Palm Kernel 80 20 25 Coconut 75 25 25 Palm Kernel 75 25 30 Coconut 70 30 30 Palm Kernel 70 30 35 Coconut 65 35 35 Palm Kernel 65 35 40 Coconut 60 40 40 Palm Kernel 60 40 45 Coconut 55 45 45 Palm Kernel 55 45 50 Coconut 50 50 50 Palm Kernel 50 50

Example 2 Oil Compositions

The oil compositions of the present invention are prepared by dissolving 25-hydroxy Vitamin D₃ and an antioxidant in an oil with heating and/or agitation, in the following proportions.

TABLE 2 Oil compositions containing an antioxidant. Amount of 25-hydroxy Amount of Amount of % wt of 25-hydroxy Vitamin D₃ (g) Oil Oil (g) Antioxidant Antioxidant (g) Vitamin D₃ 5 Coconut 85 EMQ 10 5 5 Coconut 75 BHT 20 5 5 Palm Kernel 85 EMQ 10 5 5 Palm Kernel 75 BHT 20 5 15 Coconut 75 EMQ 10 15 15 Coconut 65 BHT 20 15 15 Palm Kernel 75 EMQ 10 15 15 Palm Kernel 65 BHT 20 15 30 Coconut 60 EMQ 10 30 30 Coconut 50 BHT 20 30 30 Palm Kernel 60 EMQ 10 30 30 Palm Kernel 50 BHT 20 30 40 Coconut 50 EMQ 10 40 40 Coconut 40 BHT 20 40 40 Palm Kernel 50 EMQ 10 40 40 Palm Kernel 40 BHT 20 40 50 Coconut 40 EMQ 10 50 50 Coconut 30 BHT 20 50 50 Palm Kernel 40 EMQ 10 50 50 Palm Kernel 30 BHT 20 50

Example 3 Emulsion

An emulsion according to the present invention was prepared by dispersing an oil composition according to the present invention (e.g., those of Examples 1 and 2) in an aqueous composition.

The oil composition contained: 7.2 kg of 25-hydroxy Vitamin D₃; 27.6 kg coconut oil; and 19.88 kg EMQ. The oil composition was produced by mixing the coconut oil, EMQ, and 25-hydroxy Vitamin D₃ and heating to approximately 85° C. Stirring was continued for 90 minutes at a constant temperature. At this time, all of the crystals of 25-hydroxy Vitamin D₃ had gone into solution, as determined by viewing the solution under a microscope.

The aqueous composition contained: 376.35 kg of CAPSUL®; 78.09 kg of maltodextrin 15; 12.81 kg of sodium ascorbate; and 437.64 kg of water. To prepare the aqueous phase the ingredients were combined. With mixing and heating the dry ingredients readily dissolved in the water. The viscosity of this solution was about 385 cps.

The oil composition was added to the aqueous composition and homogenized in a homogenizer for 30 minutes. During homogenization an emulsion was formed wherein the droplets of the oil composition have a diameter of approximately 150 nm

Example 4 Microencapsulated Oil Composition

A microencapsulated oil composition of the present invention was prepared by spray drying the emulsion of Example 3 using the following parameters:

Inlet Temperature 135° C. Outlet Temperature 102° C. Microclone Inlet 4.1 Fan Inlet 14.6 Silica Feeder Set to provide about 1% Silica in dry product Atomizer RPM 17000 part A 15000 part B Pump Speed 17 part A 21 part B Product Moisture 1.9 to 2.25%

The microencapsulated oil was a tan powder having the following characteristics:

Loose Bulk Density ~0.42 g/ml Tapped Bulk Density ~0.5 g/ml Dust ~169 mg/25 g Angle of Repose ~49° Agway Flow None Loss on Drying ~2.6%

In addition, the microencapsulated oil composition showed a high degree of homogeneity as measured by UV absorptivity of the powder.

Example 5 Stability

Two batches of a microencapsulated oil composition of the present invention (Invention 001 and Invention 002) were produced as set forth below. The stability of these batches was compared to a prior art commercial product in the form of a wax beadlet. The two batches and the commercial product were all stored at either 11° C. or 25° C. for up to 4 months.

The two batches tested contained approximately 1.25% wt of 25 hydroxy Vitamin D₃ prepared according to Examples 3 and 4.

The following data demonstrate that the microencapsulated oils of the present invention exhibited greatly increased stability over the commercial product. Additionally, the microencapsulated oils of the present invention showed a slowdown in the degradation kinetic, indicating that the rate of degradation of 25-hydroxy Vitamin D₃ greatly decreases after an initial period of storage.

Storage Conditions:

The batches according to the present invention and the commercial product are stored under conventional conditions at various temperatures (see below) for period of up to 4 months.

Results:

Batch 001 displays higher initial values for 25-hydroxy Vitamin D₃ content than Batch 002.

Storage at 11° C.

As FIG. 1 shows, the compositions of the present invention displayed improved stability compared to the commercial product, at all time points, when stored at 11° C. FIG. 2 shows a plateau in the % 25-hydroxy Vitamin D₃ retention and demonstrates a slowdown of the degradation kinetic in the compositions of the present invention.

Storage at 25° C.

As FIG. 3 shows, the compositions, of the present invention displayed improved stability compared to the commercial product, at all time points, when stored at 25° C. FIG. 4 shows a plateau in the 25-hydroxy Vitamin D₃% retention at 25° C., and demonstrates a slowdown of the degradation kinetic in the compositions of the present invention.

Storage at 37° C.

At this temperature, the prior art beadlets began to degrade and form a solid block that was no longer a powder. For this reason, the prior art beadlet could not be dissolved in the solvent as usual, and no reliable retention data could be obtained. The compositions of the present invention suffered from no such degradation, and retained good flowability and bulk density at this elevated storage temperature at all time points.

FIG. 5 shows the linear regression of the retention data for the 25-hydroxy Vitamin D₃, and the commercial product at various temperatures. The regression demonstrates that the compositions of the present invention have a greatly improved stability over the commercial product at both temperatures and at all storage times. In addition, the slope of the regression curves clearly shows that the rate of degradation for the 25-hydroxy Vitamin D₃ in the microencapsulated oil compositions of the present invention is much less than that of the prior art beadlet at all storage times and temperatures. Accordingly, even after a short storage time the compositions of the present invention will retain significantly more 25-hydroxy Vitamin D₃ as compared to the prior art beadlet.

Example 6 Premix Composition

A basic premix for use in animal feed was prepared having the following components in the following proportions by percent weight based on the total weight of the premix.

TABLE 3 Premix composition COMPONENT % WEIGHT IN PREMIX 25-hydroxy Vitamin D₃, 1.25% 0.64 Vitamin A 6.40 Vitamin E 16.00 Vitamin B₁₂ 6.40 Vitamin B₃ 2.00 Niacin 8.00 Calcium Pantothenate 4.00 Vitamin K₃ 0.94 Folic Acid 0.90 Vitamin B₆ 0.96 Vitamin B₁ 0.62 Limestone 29.00 Rice Hulls 24.14

Example 7 Premix Stability

Three premixes for use in animal feed were prepared having the following components in the following proportions by percent weight based on the total weight of the premix.

TABLE 4 Composition of premixes. COMPONENT COMPLETE VITAMIN BASIC 25-hydroxy Vitamin D₃, 1.25% 0.50 1.00 1.57 Vitamin D₃ 0.64 Vitamin A 6.40 Vitamin E 0.40 16.00 Vitamin B₁₂ 6.40 Vitamin B₃ 0.05 2.00 Niacin 8.00 Calcium Pantothenate 4.00 Vitamin K₃ 0.94 Folic Acid 0.90 Vitamin B₆ 0.96 Vitamin B₁ 0.62 Carotenoids 0.20 Choline Chloride, 50% 1.50 Manganese Oxide 3.00 Zinc Oxide 0.60 Iron Sulphate (monohydrous) 1.00 Copper Oxide 0.10 Cobalt Sulphate 0.01 Oil 1.00 Limestone 28.00 19.93 Rice Hulls 24.14 77.50 Wheat Middlings 78.99

Each of these premix compositions was prepared using a microencapsulated oil of the present invention or a prior art beadlet containing 25-hydroxy Vitamin D₃. In addition, a control formulation was prepared, in which Vitamin D₃ was substituted for the 25-hydroxy Vitamin D₃. Each of the premixes was stored at 25° C. and 35° C., for a length of time up to 3 months. The percent retention of the 25-hydroxy Vitamin D₃ was determined at each time and temperature.

FIG. 6 shows the % retention of the 25-hydroxy Vitamin D₃ in the Basic Premix at each time and temperature. FIG. 7 shows the % retention of the 25-hydroxy Vitamin D₃ in the Vitamin Premix at each time and temperature. FIG. 8 shows the % retention of the 25-hydroxy Vitamin D₃ in the Complete Premix at each time and temperature.

As the results show, in the Basic and Vitamin Premixes the stability of 25-hydroxy Vitamin D₃ was less than that of Vitamin D₃. However, the stability the 25-hydroxy Vitamin D₃ was nearly identical for the prior art formulation as compared to the formulations in accordance with the present invention. (See FIGS. 6 and 7).

The results are dramatically different when the Complete Premix is considered, however. As shown in FIG. 8, the stability of the 25-hydroxy Vitamin D₃ in the prior art formulation dropped significantly as compared to the inventive formulations. As discussed above, this decrease in stability may be attributed to the oxidation of the Vitamin D₃ or 25-hydroxy Vitamin D₃ by minerals, transition metals, or peroxides found in the premix. For example, at three months storage, the prior art formulation retained less than 20% of the 25-hydroxy Vitamin D₃, whereas the formulation in accordance with the present invention retained better than 50% of the 25-hydroxy Vitamin D₃ (over 80% at a storage temperature of 25° C.).

The formulation of the present invention thus increased 25-hydroxy Vitamin D₃ retention over a wide range of temperatures and times of storage, even in premixes containing components which promote degradation of 25-hydroxy Vitamin D₃.

Example 8 Feeds

An animal feed composition was produced by combining the feed premix compositions of the present invention with an animal feed. A poultry feed was produced by mixing the premix of Example 6 with a base poultry feed having the following ingredients:

TABLE 5 Composition poultry base feed ingredients. INGREDIENT AMOUNT (% WT) Corn 50.55 Soybean Meal 40.05 Soybean Oil 5.00 Dicalcium Phosphate 1.90 Limestone 1.40 Salt 0.40 D₃-free Vitamin Mix 0.20 Mineral Mix 0.15 DL-Met 0.20 Choline 60 0.10 Bacitracin 0.025 α-Tocopherol 0.002 Ethoxyquin 0.0125

The premix and base feed were mixed until substantial homogeneity was produced.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the following claims. 

1.-35. (canceled)
 36. A method of making a microencapsulated oil comprising: providing an oil composition comprising 25-hydroxy Vitamin D₃ dissolved in an oil in an amount between about 5% and 50% by weight based on the total weight of the oil composition; and encapsulating the oil composition in an encapsulation agent to stabilize the 25-hydroxy Vitamin D.
 37. A method of making a microencapsulated oil according to claim 36 wherein the oil is present in the oil composition in an amount less than about 30% by weight based on the total weight of the microencapsulated oil composition.
 38. A method of making a microencapsulated oil according to claim 37 wherein the oil is present in the oil composition in an amount less than about 20% by weight based on the total weight of the microencapsulated oil composition.
 39. A method of making a microencapsulated oil according to claim 38 wherein the oil is present in the oil composition in an amount less than about 10% by weight based on the total weight of the microencapsulated oil composition.
 40. A method of making a microencapsulated oil according to claim 39 wherein the oil is present in the oil composition in an amount less than about 5% by weight based on the total weight of the microencapsulated oil composition.
 41. A method of making a microencapsulated oil according to claim 36 wherein the encapsulation agent is selected from the group consisting of starches, proteins from animal sources gelatins, proteins from plant sources, casein, pectin, alginate, agar, maltodextrins, lignin sulfonates, cellulose derivatives, sugars, saccharides, sorbitols, gums, and mixtures thereof.
 42. A method of making a microencapsulated oil according to claim 41 wherein the encapsulating agent is starch.
 43. A method of making a microencapsulated oil according to claim 36 wherein the encapsulating agent is starch, and the oil is coconut oil or palm kernel oil.
 44. A method of making a microencapsulated oil according to claim 36 further comprising: combining the oil composition and the aqueous composition to form an emulsion; and drying the emulsion to form the microencapsulated oil.
 45. A method of making a microencapsulated oil according to claim 44 wherein the emulsion is dried by spray drying.
 46. A method of making a microencapsulated oil according to claim 44 wherein the droplets have a mean diameter of less than about 500 nm.
 47. A method of making a microencapsulated oil according to claim 46 wherein the droplets have a mean diameter between about 100 nm and about 200 nm.
 48. A method of making a feed premix comprising: providing a microencapsulated oil composition comprising an oil composition comprising 25-hydroxy Vitamin D₃ dissolved in an oil in an amount of between about 5% and 50% by weight based on the total weight of the oil composition; and an encapsulation agent encapsulating the oil composition to stabilize the 25-hydroxy Vitamin D; and ad mixing the microencapsulated oil composition with at least one nutritional additive.
 49. A method of making a feed premix according to claim 48 wherein the nutritional additive is selected from the group consisting of vitamins, pro vitamins, minerals, active phytase, amino acids, carotenoids, starches, fish meal, choline, medicinal additives, carriers, and combinations thereof.
 50. A method of making a feed premix according to claim 48 wherein the oil is selected from the group consisting of babassu, coconut, cohune, murumyru tallow, palm kernel, tucum oil, and mixtures thereof.
 51. A method of making a feed premix according to claim 50 wherein the oil is coconut oil or palm kernel oil.
 52. A method of making a feed premix according to claim 48 wherein the encapsulating agent is selected from the group consisting of starches, proteins from animal sources (including gelatins), proteins from plant sources, casein, pectin, alginate, agar, maltodextrins, lignin sulfonates, cellulose derivatives, sugars, saccharides, sorbitols, gums, and mixtures thereof.
 53. A method of making a feed premix according to claim 52 wherein the encapsulation agent is starch.
 54. A method of making a feed premix according to claim 53 wherein the encapsulation agent is starch, and the oil is coconut oil or palm kernel oil. 